A UE of an LTE (Long Term Evolution, long term evolution) mobile communication system has two basic operation modes after being started: an idle mode and a connected mode.
Wherein, when the UE is in the connected mode, for saving power of the UE, an RRC (Radio Resource Control, radio resource control) layer of the UE will configure a DRX (Discontinuous Reception, discontinuous reception) cycle. In this way, the UE wakes up to monitor information of a PDCCH (Physical Downlink Control Channel, physical downlink control channel) in each DRX cycle, and the UE enters a sleep state after monitoring is ended.
The UE monitors a signal of a cell in each DRX cycle and measures the availability of radio resources of intra-frequency, inter-frequency and inter-system of the cell, such as received signal intensity, power and the like, the UE report a measurement result to a base station within a measurement period, and the base station determines whether the UE needs to perform cell switching and which cell the UE needs to be switched to according to the measurement result.
In the aforementioned process of monitoring and measurements of intra-frequency, inter-frequency and inter-system in the connected mode of the UE, since the period that the UE reports the measurement result is determined by the DRX cycle, for the UE in a moving speed rate, the problem that the measurement result is not reported in time may be caused, thus affecting the communication continuity of the UE.